【摘要】 以实现轻烧氧化镁为原料制备低碳磷酸镁水泥材料的3d打印为目标，采用自主研发的混搅挤功能一化建筑3d打印设备，探究了不同粉煤灰掺量对以轻烧氧化镁为基制备磷酸镁水泥材料性能与打印性能的影响规律，并结合XRD与SEM微观试验进一步分析粉煤灰对其水化产物及晶体样貌的影响。结果表明：与重烧氧化镁相比，由轻烧氧化镁制备磷酸镁水泥的凝结时间大幅缩短；粉煤灰的加入对材料凝结时间影响较小，均在2～3 min左右，但对抗压强度与界面粘结强度有负面影响，当粉煤灰掺量为磷酸镁水泥质量的30%时，抗压强度及界面粘结强度分别下降约34.24%、48.94%;粉煤灰掺量在20%以内时，可有效改善轻烧氧化镁基磷酸镁水泥材料的干缩率，提高体积稳定性；粉煤灰中的活性物质参与水化反应，生成的水化产物与磷酸镁水泥展现出良好的化学相容性，使结构内部更为密实；当粉煤灰掺量为20%～25%时，制备的3d打印用轻烧氧化镁基磷酸镁水泥具有良好的工作性能、体积稳定性能、挤出性能以及建造性能，且满足3d打印对水泥基材料的力学要求。更多还原

【Abstract】 In this paper, the goal is to realize the 3d Printing of low-carbon magnesium phosphate cement materials prepared from light-burned magnesium oxide as raw material. With the help of the self-developed mixing and extrusion function-based building 3d Printing equipment, the influence of different fly ash content on the properties and printing properties of magnesium phosphate cement materials prepared from light-burned magnesium oxide was investigated. The influence of fly ash on its hydration products and crystal appearance was further analyzed by XRD and SEM micro-tests. The results show that the setting time of magnesium phosphate cement prepared from light burned magnesium oxide is greatly shortened compared with that of heavy burned magnesium oxide. The addition of fly ash has a little effect on the setting time of the material, which is about 2-3 min, but it has a negative effect on the compressive strength and interfacial bond strength. When the content of fly ash is 30% of the mass of magnesium phosphate cement, the compressive strength and interfacial bond strength decrease by about 34.24% and 48.94%, respectively. When the content of fly ash is less than 20%, it can effectively improve the dry shrinkage rate of light-burned magnesia-based magnesium phosphate cement material and increase the volume stability. The active substances in fly ash participate in the hydration reaction, and the generated hydration products show good chemical compatibility with magnesium phosphate cement, making the structure more compact. When the content of fly ash is 20%-25%, the prepared light burned MgO-based magnesium phosphate cement for 3d Printing has good working performance, volume stability, extrusion performance and construction performance, and meets the mechanical requirements of 3d Printing for cement-based materials.更多还原